The murder of a US ambassador at the American consulate in Benghazi, Libya, was a "deliberate" and planned "revenge attack" according to Intelligence group Quilliam.
It said the attack was to avenge the killing of Abu al Libi, a veteran al Qaeda militant killed in a US drone strike earlier this year.
The Taliban has meanwhile called on Afghans to prepare for a fight against Americans and urged insurgents to "take revenge" on US soldiers over the American Anti-Islamic film that apparently motivated yesterday's consulate mob attack.
A Pakistani minister offered $100,000 (£61,600) on Saturday for the death of an online filmmaker.
US Embassies across the Muslim world have come under attack and a US school in Tunisia set on fire in protests against the anti-Islam film.
Protests against the anti-Islam film continue to spread with the US embassy in Yemen stormed, while protests continue in Egypt and Iraq.